Binding and molecular basis of the bat coronavirus RaTG13 virus to ACE2 in humans and other species.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide, causing a global pandemic. Bat-origin RaTG13 is currently the most phylogenetically related virus. Here we obtained the complex structure of the RaTG13 receptor binding domain (RBD) with human ACE2 (hACE2) and evaluated binding of RaTG13 RBD to 24 additional ACE2 orthologs. By substituting residues in the RaTG13 RBD with their counterparts in the SARS-CoV-2 RBD, we found that residue 501, the major position found in variants of concern (VOCs) 501Y.V1/V2/V3, plays a key role in determining the potential host range of RaTG13. We also found that SARS-CoV-2 could induce strong cross-reactive antibodies to RaTG13 and identified a SARS-CoV-2 monoclonal antibody (mAb), CB6, that could cross-neutralize RaTG13 pseudovirus. These results elucidate the receptor binding and host adaption mechanisms of RaTG13 and emphasize the importance of continuous surveillance of coronaviruses (CoVs) carried by animal reservoirs to prevent another spillover of CoVs.

Integrating DNA/RNA microbe detection and host response for accurate diagnosis, treatment and prognosis of childhood infectious meningitis and encephalitis.

BACKGROUND: Infectious meningitis/encephalitis (IM) is a severe neurological disease that can be caused by bacterial, viral, and fungal pathogens. IM suffers high morbidity, mortality, and sequelae in childhood. Metagenomic next-generation sequencing (mNGS) can potentially improve IM outcomes by sequencing both pathogen and host responses and increasing the diagnosis accuracy. METHODS: Here we developed an optimized mNGS pipeline named comprehensive mNGS (c-mNGS) to monitor DNA/RNA pathogens and host responses simultaneously and applied it to 142 cerebrospinal fluid samples. According to retrospective diagnosis, these samples were classified into three categories: confirmed infectious meningitis/encephalitis (CIM), suspected infectious meningitis/encephalitis (SIM), and noninfectious controls (CTRL). RESULTS: Our pipeline outperformed conventional methods and identified RNA viruses such as Echovirus E30 and etiologic pathogens such as HHV-7, which would not be clinically identified via conventional methods. Based on the results of the c-mNGS pipeline, we successfully detected antibiotic resistance genes related to common antibiotics for treating Escherichia coli, Acinetobacter baumannii, and Group B Streptococcus. Further, we identified differentially expressed genes in hosts of bacterial meningitis (BM) and viral meningitis/encephalitis (VM). We used these genes to build a machine-learning model to pinpoint sample contaminations. Similarly, we also built a model to predict poor prognosis in BM. CONCLUSIONS: This study developed an mNGS-based pipeline for IM which measures both DNA/RNA pathogens and host gene expression in a single assay. The pipeline allows detecting more viruses, predicting antibiotic resistance, pinpointing contaminations, and evaluating prognosis. Given the comparable cost to conventional mNGS, our pipeline can become a routine test for IM.

Removing Negative Impacts from Inevitable Nonreproducible and Nonspecific Antibody-Probe Interactions in Viral Serology.

Serological assays are indispensable tools in public health. Presently deployed serological assays, however, largely overlook research progress made in the last two decades that jeopardizes the conceptual foundation of these assays, i.e., antibody (Ab) specificity. Challenges to traditional understanding of Ab specificity include Ab polyspecificity and most recently nonreproducible Ab-probe interactions (NRIs). Here, using SARS-CoV-2 and four common livestock viruses as a test bed, we developed a new serological platform that integrates recent understanding about Ab specificity. We first demonstrate that the response rate (RR) from a large-sized serum pool (∼100) is not affected by NRIs or by nonspecific Ab-probe interactions (NSIs), so RR can be incorporated into the diagnostic probe selection process. We subsequently used multiple probes (configured as a "protein peptide hybrid microarray", PPHM) to generate a digital microarray index (DMI) and finally demonstrated that DMI-based analysis yields an extremely robust probabilistic trend that enables accurate diagnosis of viral infection that overcomes multiple negative impacts exerted by NSI/NRI. Thus, our study with SARS-CoV-2 confirms that the PPHM-RR-DMI platform enables very rapid development of serological assays that outperform traditional assays (for both sensitivity and specificity) and supports that the platform is extendable to other viruses.

Six-month repeated irradiation of 650 nm low-level red light reduces the risk of myopia in children: a randomized controlled trial.

PURPOSE: To evaluate whether the six-month repeated irradiation of 650 nm low-level red light (LLRL) decreases the risk of myopia onset in children. METHODS: This was a single-masked, randomized controlled trial. A total of 112 children (aged 6-12 years) were enrolled and randomized to the treatment group or control group in a 1:1 ratio. The cycloplegic spherical equivalent error (SER) of children at baseline was -0.5 diopter (D) to 3D. Children in the treatment group were irradiated with the 650 nm LLRL for 6 min daily. No intervention was given to the control. The primary outcomes are myopia incidence, change in cycloplegic SER, and change in axial length (AL). RESULTS: For the treatment group and control group, the six-month myopia incidence rates were 1.8% (95% confidence interval, CI: 0.2-4.9%) and 12.5% (95% CI: 5.5-21.9%), respectively. The difference was significant (p = 0.028). The median changes in AL for the treatment group and control group were -0.02 (interquartile range, IQR: -0.12 to 0.06) mm, and 0.09 (IQR: 0-0.18) mm, respectively. The difference was significant (p < 0.001). The median changes in cycloplegic SER for the treatment group and control group were 0 (IQR: 0-0.25) D, and -0.125 (IQR: -0.375 to 0) D, respectively. The difference was significant (p < 0.001). There was no adverse event. CONCLUSION: The repeated irradiation of 650 nm LLRL may have a strong effect for myopia prevention in children, without risk of adverse events. TRIAL REGISTRATION: this trial is retrospectively registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ), the registration number is ChiCTR2200058963.

Comparison and development of a metagenomic next-generation sequencing protocol for combined detection of DNA and RNA pathogens in cerebrospinal fluid.

BACKGROUND: The purpose of this study was to evaluate different pretreatment, extraction, amplification, and library generation methods for metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) and to develop an efficient procedure for the simultaneous detection of DNA and RNA pathogens. METHODS: We generated thirteen mock CSF samples with four representative pathogens of encephalitis. Each sample was subjected to ten different methods by varying sample pretreatment/nucleic acid extraction (microbial DNA, total DNA, total NA, total RNA, Whole Transcriptome Amplification (WTA)) and library generation (Illumina or NEB). Negative extraction controls (NECs) were used for each method variation. RESULTS: We found that the quality of mNGS sequencing reads was higher from the NEB kit for library generation. Microbial DNA and total RNA increased microbial deposition by depleting the host DNA. Methods total NA and total RNA can detect gram-positive, gram-negative, RNA and DNA pathogens. We applied mNGS, including total NA and NEB library generation, to CSF samples from five patients diagnosed with infectious encephalitis and correctly determined all pathogens identified in clinical etiological tests. CONCLUSIONS: Our findings suggested that total nucleic acid extraction combined with NEB library generation is the most effective mNGS procedure in CSF pathogen detection. The optimization of positive criteria and databases can improve the specificity and sensitivity of mNGS diagnosis. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800015425 (29/03/2018), https://www.chictr.org.cn/edit.aspx?pid=26292&htm=4 .

The etiology of acute meningitis and encephalitis syndromes in a sentinel pediatric hospital, Shenzhen, China.

BACKGROUND: Acute meningitis and encephalitis syndromes (AMES) is a severe neurological infection which causes high case fatality and severe sequelae in children. To determine the etiology of childhood AMES in Shenzhen, a hospital-based study was undertaken. METHODS: A total of 240 cerebrospinal fluid (CSF) samples from 171 children meeting the case definition were included and screened for 12 common causative organisms. The clinical data and conventional testing results were collected and analyzed. Whole genome sequencing was performed on a Neisseria meningitidis isolate. RESULTS: A pathogen was found in 85 (49.7%) cases; Group B Streptococcus (GBS) was detected in 17 cases, Escherichia coli in 15, Streptococcus pneumoniae in 14, enterovirus (EV) in 13, herpes simplex virus (HSV) in 3, N. meningitidis in 1, Haemophilus influenzae in 1, and others in 23. Notably, HSV was found after 43 days of treatment. Twelve GBS and 6 E. coli meningitis were found in neonates aged less than 1 month; 13 pneumococcal meningitis in children aged > 3 months; and 12 EV infections in children aged > 1 year old. The multilocus sequence typing of serogroup B N. meningitidis isolate was ST-3200/CC4821. High resistance rate to tetracycline (75%), penicillin (75%), and trimethoprim/sulfamethoxazole (75%) was found in 4 of S. pneumoniae isolates; clindamycin (100%) and tetracycline (100%) in 9 of GBS; and ampicillin (75%) and trimethoprim/sulfamethoxazole (67%) in 12 of E. coli. CONCLUSIONS: The prevalence of N. meningitidis and JEV was very low and the cases of childhood AMES were mainly caused by other pathogens. GBS and E. coli were the main causative organisms in neonates, while S. pneumoniae and EV were mainly found in older children. HSV could be persistently found in the CSF samples despite of the treatment. A better prevention strategy for GBS, the introduction of pneumococcal vaccine, and incorporation of PCR methods were recommended.

Effects of dietary fibre level and body weight of pigs on nutrient digestibility and available energy in high-fibre diet based on wheat bran or sunflower meal.

The objectives of this study were (a) to investigate the effect of body weight (BW) on available energy in fibre-rich diets containing two NDF levels; and (b) to evaluate the effect of fibre type and NDF level on AA digestibility. In Exp. 1, barrows (24 at 33.4 ± 1.1 kg; 24 at 86.8 ± 3.3 kg) were randomly allotted to 4 diets containing a high protein basal (HPB), a low protein basal (LPB), 70% HPB + 30% wheat bran (WB) (HPB-WB) and 70% LPB + 30% sunflower meal (SFM) (LPB-SFM). In Exp. 2, barrows (24 at 33.5 ± 1.8 kg; 24 at 87.0 ± 3.8 kg) were randomly allotted to 4 diets containing no SFM with 12% NDF (SFM0LF), no SFM with 16% NDF (SFM0HF), 24% SFM with 12% NDF (SFM24LF) and 24% SFM with 16% NDF (SFM24HF). In Exp. 3, twelve barrows (35.5 ± 3.4 kg) fitted with T-cannulas were allotted to two 6 × 4 Youden square design with 6 diets (4 same diets as in Exp. 2 and 2 nitrogen-free diets). The concentration of DE, ME and ATTD of GE, CP, NDF and ADF in diets was greater (p < .01) when fed to 90 kg pigs compared with 30 kg pigs. The ME in ingredients was not affected by BW. The ATTD of NDF was negatively correlated with the CF (r = -.98; p < .01), ADF (r = -.99; p < .01) and ADL content (r = -.96; p < .01). The ME of diets was negatively correlated with the ATTD of CF (r = -.98; p < .01). The addition of SFM increased the standardized ileal digestibility (SID) of Met (p < .05). In conclusion, diets rich in fibre had different nutritional values at different pig weight stages. The AA digestibility depends mainly on chemical composition of diets.

Determination of the energy contents and nutrient digestibility of corn, waxy corn and steam-flaked corn fed to growing pigs.

Objective: The research was conducted to determine the DE and ME contents as well as the apparent total tract digestibility (ATTD) of nutrients in corn, waxy corn and steam-flaked corn fed to growing pigs. Methods: Eighteen growing pigs with initial body weight of 15.42 ± 1.41 kg were randomly allotted to three diets including a corn diet, a waxy corn diet and a steam-flaked corn diet in a completely randomized design. Each treatment contained six replicates. The experiment lasted for 12 days, which comprised 7-d adaptation to diets followed by a 5-d total collection of feces and urine. The energy contents and the nutrient digestibility in three ingredients were calculated using direct method. Results: Compared to normal corn, both the amylose and dietary fiber contents in waxy corn were numerically lower, but the starch gelatinization degree was numerically greater. Moreover, the DE and ME contents as well as the ATTD of NDF and ADF in waxy corn were significantly greater (p < 0.05) than those in normal corn when fed to growing pigs. Furthermore, the steam-flaked corn had greater (p < 0.05) DE and ME contents, and ATTD of ether extract (EE) and ADF compared to normal corn. Conclusion: Both variety and processing procedure have influence on chemical compositions, energy contents and nutrient digestibility of corn. The waxy corn and steam-flaked corn had greater starch gelatinization degree and DE and ME contents compared to normal corn when fed to growing pigs.

Effect of keratinase on ileal amino acid digestibility in five feedstuffs fed to growing pigs.

OBJECTIVE: This study was conducted to evaluate the effect of keratinase (KE) on the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) in rice bran, cottonseed meal (CSM), rapeseed meal (RSM), corn distillers dried grains with solubles (DDGS), and peanut meal (PNM). METHODS: Twelve crossbred barrows (Duroc×Landrace×Yorkshire, 50.5±1.4 kg body weight [BW]) fitted with T-cannulas at the terminal ileum were allotted to a 12×6 Youden Square design with 12 diets and 6 periods. The treatment diets included rice bran, CSM, RSM, corn DDGS, PNM, or corn-soybean meal (cSBM) supplemented with 0.05% KE or not. Diets were given to pigs at a level of 3% BW in two equal meals. The endogenous AA losses were the mean results of three previously experiments determined by a same nitrogen-free diet fed to pigs. Pigs had free access to water during the experiment. RESULTS: The KE supplementation improved (p<0.05) the AID and SID of Met, Thr, Val, Asp, Cys, and Tyr in rice bran. Inclusion of KE increased (p<0.05) the AID and SID of Met and Val in CSM. The KE supplementation decreased (p<0.05) the AID and SID of His in RSM and all measured AA except for Arg, Met, Trp, Val, Gly, and Pro in corn DDGS. There was an increase (p<0.05) in AID and SID of Leu, Ile, Met, Ala, Cys, Ser, and Tyr in PNM supplemented with KE compared with that without KE. Inclusion of KE increased (p<0.05) the AID and SID of crude protein, Leu, Ile, Phe, Thr, Asp, and Ser in cSBM. CONCLUSION: This study indicated that KE had different effects on ileal AA digestibility of feedstuffs for growing pigs, which can give some usage directions of KE in swine feed containing those detected feedstuffs.

[Clinical features and genetic analysis of a case with carnitine palmitoyltransferase 1A deficiency].

OBJECTIVE: To analyze the clinical and molecular features of a child with carnitine palmitoyltransferase 1A (CPT1A) deficiency. METHODS: Clinical data of the child was collected. Blood acylcarnitine was determined with tandem mass spectrometry. DNA was extracted from the child and his parents. All exons and flanking regions of the CPT1A gene were analyzed by PCR and Sanger sequencing. RESULTS: Analysis showed that the patient carried compound heterozygous mutations c.1787T>C and c.2201T>C of the CPT1A gene, which derived his father and mother, respectively. Both mutations were verified as novel through the retrieval of dbSNP, HGMD and 1000 genome databases. Bioinformatic analysis suggested that the mutations can affect protein function. CONCLUSION: Acyl carnitine analysis has been the main method for the diagnosis of CPT1A deficiency. The c.1787T>C and c.2201T>C mutations of the CPT1A gene probably underlie the disease in this patient. Gene testing can provide important clues for genetic counseling and prenatal diagnosis.

[Establishment of reference ranges of sex hormones for healthy children in Shenzhen, China based on chemiluminescence].

OBJECTIVE: To study the reference ranges of six sex hormones, i.e., luteinizing hormone, follicle-stimulating hormone, progesterone, prolactin, estradiol, and testosterone, for healthy children aged 0-18 years in Shenzhen, China. METHODS: Stratified cluster sampling was performed to select 2 178 healthy children aged 0-18 years in the districts of Futian, Luohu, Nanshan, Bao'an, and Longgang in Shenzhen between September 2015 and September 2016. There were 1 219 boys and 959 girls, including 81 neonates, 335 infants, 346 young children, 469 preschool children, 419 school-aged children, and 528 adolescents. The American Beckman DXI800 chemiluminescence meter was used to measure the levels of luteinizing hormone, follicle-stimulating hormone, progesterone, prolactin, estradiol, and testosterone. RESULTS: There were significant differences in the levels of luteinizing hormone, follicle-stimulating hormone, progesterone, prolactin, estradiol, and testosterone between different age groups (P<0.05). There were also significant differences in the levels of these sex hormones between boys and girls in the same age group (P<0.05). The reference ranges of six sex hormones were established for healthy children aged 0-18 years in Shenzhen based on the levels of these hormones in different age groups. CONCLUSIONS: There are significant differences in sex hormones between different age groups or sex groups. The reference ranges of six sex hormones established for different sexes or ages have great significance in the diagnosis and treatment of endocrine diseases in children.

McTwo: a two-step feature selection algorithm based on maximal information coefficient.

BACKGROUND: High-throughput bio-OMIC technologies are producing high-dimension data from bio-samples at an ever increasing rate, whereas the training sample number in a traditional experiment remains small due to various difficulties. This "large p, small n" paradigm in the area of biomedical "big data" may be at least partly solved by feature selection algorithms, which select only features significantly associated with phenotypes. Feature selection is an NP-hard problem. Due to the exponentially increased time requirement for finding the globally optimal solution, all the existing feature selection algorithms employ heuristic rules to find locally optimal solutions, and their solutions achieve different performances on different datasets. RESULTS: This work describes a feature selection algorithm based on a recently published correlation measurement, Maximal Information Coefficient (MIC). The proposed algorithm, McTwo, aims to select features associated with phenotypes, independently of each other, and achieving high classification performance of the nearest neighbor algorithm. Based on the comparative study of 17 datasets, McTwo performs about as well as or better than existing algorithms, with significantly reduced numbers of selected features. The features selected by McTwo also appear to have particular biomedical relevance to the phenotypes from the literature. CONCLUSION: McTwo selects a feature subset with very good classification performance, as well as a small feature number. So McTwo may represent a complementary feature selection algorithm for the high-dimensional biomedical datasets.

[One-step multiplex RT-PCR for identifying common fusion transcripts in childhood acute lymphoblastic leukemia].

OBJECTIVE: To evaluate the efficiency of one-step multiplex RT-PCR for identifying four common fusion transcripts (TEL/AML1, E2A/PBX1, MLL/AF4 and BCR/ABL) in children with acute lymphoblastic leukemia (ALL). METHODS: Total RNA was extracted from bone marrow samples of 76 children who were newly diagnosed with ALL between January 2003 and December 2010. These RNAs were analyzed for TEL/AML1, E2A/PBX1, MLL/AF4 and BCR/ABL by one-step multiplex RT-PCR or common nested-multiplex PCR. The PCR products were confirmed by DNA sequencing. RESULTS: TEL/AML1 was found in 12 cases (the length of products was 298 bp in 9 cases and 259 bp in 3 cases), E2A/PBX1 was found in 3 cases (the length of products was 373 bp), BCR/ABL was found in 1 case (the length of products was 2 124 bp), and MLL/AF4 was found in 7 cases (the length of products was 427 bp in 1 case and 673 bp in 6 cases) using one-step multiplex RT-PCR combined with DNA sequencing. The results were consistent with those using common nested-multiplex PCR. CONCLUSIONS: One-step multiplex RT-PCR may be another alternative for detection of common fusion transcripts in children with ALL.

[SCD1 over-expression inhibits palmitic acid-induced apoptosis of rat BRL hepatocytes].

OBJECTIVE: To investigate the protective mechanism of stearoyl-CoA desaturase 1 (SCD1) over-expression against the pro-apoptotic affects of palmitic acid on hepatocytes using the rat BRL cell line. METHODS: Concentration effect curves were generated using the trypan blue exclusion test to assess the death rate of BRL cells upon exposure to a dilution series of palmitic acid. The multiplicity of infection (MOI) of a lentiviral expression vector, pGC-FU-GFP, was determined for the BRL cells. Unmanipulated BRL cells were divided into two groups: the non-palmitate groups were composed of ordinary cultured cells (CON) alone, infected with lentivirus empty expression vector (negative control, NC), and infected with lentivirus overexpressing SCD1 (SCD1-LV); the palmitate groups were composed of ordinary cultured cells plus palmitate (CON+) alone, infected with lentivirus empty expression vector plus palmitate (NC+), and infected with lentivirus overexpressing SCD1 plus palmitate (SCD1-LV+). SCD1 mRNA expression was detected by real-time PCR. Propidium iodide (PI) single-staining was used to detect apoptosis and assess the cell cycle. Inter-group differences were analyzed statistically. RESULTS: The death rate of BRL cells increased significantly after 72 h of exposure to 400 mumol/L palmitate (P less than 0.01). The MOI of pGC-FU-GFP in BRL cells was 20. The expression of SCD1 was significantly higher in the SCD1-LV and SCD1-LV+ groups than in the respective controls (vs. CON: F = 289, P less than 0.01; vs. CON+: F = 1522, P less than 0.01). Palmitate exposure led to decreased expression of SCD1 (CON+ vs. CON, F = 22, P less than 0.05 and NC+ vs. NC: F = 34, P less than 0.05). The ratio of S stage cells was similar in all non-palmitate groups (CON, NC and SCD1-LV, P = 0.137). However, there was a significant apoptotic peak and lower ratio of S stage cells in the control palmitate groups (CON+ and NC+) and the activity of cell proliferation was decreased as well. The ratio of apoptotic cells was decreased significantly in the SCD1-LV+ group compared to the CON+ group (P less than 0.01). CONCLUSION: The expression of SCD1 and its desaturation activity increased in BRL cells upon infection with the pGC-FU-SCD1-GFP lentiviral vector, suggesting that SCD1 over-expression can decrease palmitic acid-induced toxicity and apoptosis in hepatocytes.

Daily Low-Level Red Light for Spherical Equivalent Error and Axial Length in Children With Myopia: A Randomized Clinical Trial.

Importance: Treatments are needed to slow progression of or reduce incidence of myopia. Objective: To evaluate the efficacy and safety of daily 650-nm low-level red light (LLRL) for myopia treatment. Design, Setting, and Participants: Single-masked, randomized clinical trial at 1 site in China. Baseline measurements were completed from August to September 2021. Participants were children aged 6 to 12 years with spherical equivalent error (SER) of -6 diopters (D) to 3 D. Data were analyzed from March to July 2023. Interventions: Irradiation daily with 650-nm LLRL for 3 minutes twice daily 4 or more hours apart or no intervention. Main Outcomes and Measures: Primary outcomes were changes in cycloplegia SER and axial length (AL) at 6- and 12-month follow-up visits. Safety was assessed on masked fundus photograph evaluations. Results: A total of 336 children were randomly allocated into the LLRL group or control group in a 1:1 ratio. The control group contained 86 female patients (51.2%), and the treatment group contained 90 female patients (53.6%). The mean (SD) age, SER, and AL were 9.0 (1.9) years, -1.3 (1.5) D, and 23.8 (1.0) mm for all patients. A total of 161 (95.8%) in the LLRL group and 159 (94.6%) in the control group returned for the 6-month follow-up. A total of 157 (93.5%) in the LLRL group and 152 (90.5%) in the control group returned for the 12-month follow-up. Mean (SD) changes in SER were 0.15 (0.16) D and -0.26 (0.21) D for the LLRL group and the control group, respectively (difference, -0.41 D; 95% CI, -0.48 to -0.34 D; P < .001), at 6 months and 0.24 (0.27) D and -0.65 (0.33) D for the LLRL group and the control group, respectively (difference, -0.89 D; 95% CI, -0.95 to -0.83 D; P < .001), at 12 months. Mean (SD) changes in AL were -0.06 (0.08) mm and 0.13 (0.12) mm for the LLRL group and control group, respectively (difference, 0.19 mm; 95% CI, 0.16 to 0.22 mm; P < .001), at 6 months and -0.11 (0.10) mm and 0.26 (0.16) mm for the LLRL group and control group, respectively (difference, 0.37 mm; 95% CI, 0.34 to 0.40 mm; P < .001). Masked fundus photograph review did not identify retinal changes in either group. Conclusions and relevance: These findings suggest daily use of 650-nm LLRL for 1 year can slow progression of SER and AL without safety concerns identified. Confirmation of these findings at independent sites seems warranted, as well as determining whether these effects can be sustained with or without continued treatment and whether LLRL has any effect on pathological myopia. Trial Registration: ChiCTR2200058963.

Extraction process and characterization of Taraxacum kok-saghyz (TKS) latex.

Taraxacum kok-saghyz (TKS) latex is a natural latex produced from its root, and its extraction optimization process is mainly studied in the present paper. The composition of fresh roots of TKS was quantitatively analyzed, and the results showed that the moisture content of the fresh root was approximately 70 %, and the rubber content averaged to 6 % (dry weight ratio). An optimal process route for extracting the TKS latex was finally determined, making the extraction efficiency reach about 80 %, and a new latex extraction process was established and optimized and named "the process of Buffer Extraction TKS Latex (BETL)". Hevea latex, extracted TKS latex and TKS latex collected directly from the broken roots were compared for study. The results showed that, like Hevea latex, the appearance of TKS latex was milky white; and after centrifugation, both showed four layers from top to bottom: rubber particles, Frey-Wyssling particles, C-serum and lutoids. The results of the composition analysis showed that the concentration of TKS latex ranged from 54.54 % to 68.25 %, which is close to that of concentrated Hevea latex; the moisture content of TKS latex was between 31.75 % and 45.46 %. The protein content of TKS latex was 13.51 mg/mL, which was lower than that of Hevea latex at the same rubber hydrocarbon concentration. The molecular structures and properties of Hevea latex, the extracted TKS latex, and the collected TKS latex were characterized by FTIR, 13C NMR, GPC, TG, SEM and LPSA, and the results showed that the main components and structure of the three latexes were similar, which are all cis-1,4-polyisoprene, and include the proteins and lipids. The distributions molecular weights of the three latexes all showed a bimodal distribution, but the molecular weight of the latex collected from TKS was lower, which indicates the larger molecules were difficult to flow outside the root automatically. The Hevea latex and TKS latex rubber particles were both core-shell structure and the size distribution were bimodal, which was consistent with the GPC analysis results.

Rapid and One-tube detection of Human Metapneumovirus using the RT-RPA and CRISPR/Cas12a.

Human metapneumovirus (HMPV) is a common pathogen that can cause acute respiratory tract infections and is prevalent worldwide. There is yet no effective vaccine or specific treatment for HMPV. Early, rapid, and accurate detection is essential to treat the disease and control the spread of infection. In this study, we created the One-tube assay by combining Reverse Transcription-Recombinase Polymerase Amplification (RT-RPA) with the CRISPR/Cas12a system. By targeting the nucleoprotein (N) gene of HMPV to design specific primers and CRISPR RNAs (crRNAs), combining RT-RPA and CRISPR/Cas12a, established the One-tube assay. Meanwhile, the reaction conditions of the One-tube assay were optimized to achieve rapid and visual detection of HMPV. This assay could detect HMPV at 1 copy/µL in 30min, without cross-reactivity with nine other respiratory pathogens. We validated the detection performance using clinical specimens and showed that the coincidence rate was 98.53%，compared to the quantitative reverse-transcription polymerase chain reaction. The One-tube assay reduced the detection time and simplified the manual operation, while maintaining the detection performance and providing a new platform for HMPV detection.

PPAR-γ Activation Alleviates Osteoarthritis through Both the Nrf2/NLRP3 and PGC-1α/Δψ m Pathways by Inhibiting Pyroptosis.

Osteoarthritis (OA) is a common degenerative joint disease with a gradually increasing morbidity in the aging and obese population. Emerging evidence has implicated pyroptosis in the etiology of OA and it may be recognized as a therapeutic target in OA. We have previously reported regarding another disease that peroxisome proliferator-activated receptor gamma (PPAR-γ) activation exerts an anti-inflammatory effect by suppressing the nucleotide-binding and oligomerization domain-like receptor containing protein (NLRP) 3 inflammasome. However, the relationship between PPAR-γ and NLRP3-mediated pyroptosis in OA cartilage and its underlying mechanisms is fully unclear. In this study, we found that the level of NLRP3-mediated pyroptosis in severe lateral femoral condyle cartilage wear in the knee of an OA patient was significantly higher than that in the mild lateral femoral condyle cartilage wear areas. Moreover, in lipopolysaccharide (LPS)/adenosine triphosphate (ATP)-induced primary chondrocytes and knee OA rat models, we demonstrated that activation of PPAR-γ by pioglitazone (Piog) attenuated LPS/ATP-induced chondrocyte pyroptosis and arthritis. These effects were partially counteracted by either blocking the nuclear factor erythroid-2-related factor (Nrf2)/NLRP3 or PGC1-α/Δψ m signaling pathway. Simultaneous depression of these two signaling pathways can completely abrogate the protective effects of Piog on OA and chondrocytes. Taken together, Piog protects OA cartilage against pyroptosis-induced damage by simultaneously activating both the Nrf2/NLRP3 and PGC-1α/Δψ m pathways, which enhances antioxidative and anti-inflammatory responses as well as mitochondrial biogenesis. Therefore, Piog may be a promising agent for human OA cartilage damage in future clinical treatments.

Performance of targeted next-generation sequencing in the detection of respiratory pathogens and antimicrobial resistance genes for children.

Introduction. Respiratory tract infection, which is associated with high morbidity and mortality, occurs frequently in children. At present, the main diagnostic method is culture. However, the low pathogen detection rate of the culture approach prevents timely and accurate diagnosis. Fortunately, next-generation sequencing (NGS) can compensate for the deficiency of culture, and its application in clinical diagnostics has become increasingly available.Gap Statement. Targeted NGS (tNGS) is a platform that can select and enrich specific regions before data enter the NGS pipeline. However, the performance of tNGS in the detection of respiratory pathogens and antimicrobial resistance genes (ARGs) in infections in children is unclear.Aim and methodology. In this study, we estimated the performance of tNGS in the detection of respiratory pathogens and ARGs in 47 bronchoalveolar lavage fluid (BALF) specimens from children using conventional culture and antimicrobial susceptibility testing (AST) as the gold standard.Results. RPIP (Respiratory Pathogen ID/AMR enrichment) sequencing generated almost 500 000 reads for each specimen. In the detection of pathogens, RPIP sequencing showed targeted superiority in detecting difficult-to-culture bacteria, including Mycoplasma pneumoniae. Compared with the results of culture, the sensitivity and specificity of RPIP were 84.4 % (confidence interval 70.5-93.5 %) and 97.7 % (95.9 -98.8%), respectively. Moreover, RPIP results showed that a single infection was detected in 10 of the 47 BALF specimens, and multiple infections were detected in 34, with the largest number of bacterial/viral coinfections. Nevertheless, there were also three specimens where no pathogen was detected. Furthermore, we analysed the drug resistance genes of specimens containing Streptococcus pneumoniae, which was detected in 25 out of 47 specimens in the study. A total of 58 ARGs associated with tetracycline, macrolide-lincosamide-streptogramin, beta-lactams, sulfonamide and aminoglycosides were identified by RPIP in 19 of 25 patients. Using the results of AST as a standard, the coincidence rates of erythromycin, tetracycline, penicillin and sulfonamides were 89.5, 79.0, 36.8 and 42.1 %, respectively.Conclusion. These results demonstrated the superiority of RPIP in pathogen detection, particularly for multiple and difficult-to-culture pathogens, as well as in predicting resistance to erythromycin and tetracycline, which has significance for the accurate diagnosis of pathogenic infection and in the guidance of clinical treatment.

[Genetic factors in the occurrence of neonatal unconjugated hyperbilirubinemia].

OBJECTIVE: To study association of uridine-diphosphate-glucuronosyltransferase1A1 (UGT1A1) Gly71Arg, UGT1A1 promoter TATA-box and glucose-6-phosphate dehydrogenase (G6PD) gene mutations with the occurrence of neonatal unconjugated hyperbilirubinemia. METHODS: The TATA-box, exon 1 and exon 5 of the UGT1A1 gene and the exon 12 of G6PD gene were amplified by PCR. The products of PCR were analyzed by direct DNA sequencing. Clones for the mutations of the UGT1A1 gene and the G6PD gene were constructed in order to identify the results of the products of PCR. Seventy-two neonates with unconjugated hyperbilirubinemia (case group) and 65 healthy neonates (control group) were enrolled. The genotypes and allele frequencies of the polymorphisms of UGT1A1 Gly71Arg and UGT1A1 TATA-box were compared between the two groups. The effects of UGT1A1 Gly71Arg, UGT1A1 promoter TATA-box and G6PD gene mutations on the development of neonatal unconjugated hyperbilirubinemia were estimated using logistic regression models. RESULTS: There were significant differences in the genotype distribution of Gly71Arg polymorphism of UGT1A1 gene between the case and control groups (P<0.01). The Arg allele frequency of the polymorphisms of UGT1A1 gene in the case group was significantly higher than in the control group (P<0.01). There were no significant differences in the genotype distribution of the UGT1A1 promoter TATA-box between the two groups (P>0.05). The OR and 95%CI values of UGT1A1 Gly71Arg, UGT1A1 TATA-box and G6PD gene mutations associated with the development of neonatal unconjugated hyperbilirubinemia were 5.468 (2.274, 12.818), 0.688 (0.266, 1.778) and 5.081 (1.070, 24.133) respectively. CONCLUSIONS: UGT1A1 Gly71Arg and G6PD gene mutations may be involved in the development of neonatal unconjugated hyperbilirubinemia.